Collision avoidance adaptation for autonomous transmission systems

ABSTRACT

A method in a wireless device ( 110 ) comprises obtaining ( 1004 ) information related to a signal transmission configuration for autonomous uplink transmission by the wireless device, the information comprising: a set of pre-allocated resources for use by the wireless device in performing autonomous uplink transmission on at least one secondary cell established between the wireless device and a network node ( 115 ); and a periodicity associated with the set of pre-allocated resources. The method comprises performing ( 1008 ) autonomous uplink transmission according to the obtained information related to the signal transmission configuration.

PRIORITY

This non-provisional application is a continuation of Ser. No.16/880,144, now U.S. Pat. No. 11,363,521, filed May 21, 2020, which wasa divisional application of Ser. No. 15/579,460, now U.S. Pat. No.10,708,851, filed Dec. 4, 2017, which is a U.S. National Stage Filingunder 35 U.S.C. § 371 of International Patent Application Serial No.PCT/SE2017/051040 filed Oct. 23, 2017, and entitled “Collision AvoidanceAdaptation for Autonomous Transmission Systems,” which claims priorityto U.S. Provisional Patent Application No. 62/412,388 filed Oct. 25,2016, each of which is hereby incorporated by reference in theirentirety.

TECHNICAL FIELD

The present disclosure relates, in general, to wireless communicationsand, more particularly, to collision avoidance adaptation for autonomoustransmission systems.

BACKGROUND

The 3^(rd) Generation Partnership Project (3GPP) work onLicensed-Assisted Access (LAA) intends to allow Long Term Evolution(LTE) equipment to also operate in the unlicensed radio spectrum.Candidate bands for LTE operation in the unlicensed spectrum include 5GHz and 3.5 GHz, among others. The unlicensed spectrum can be used as acomplement to the licensed spectrum, but also allows completelystandalone operation.

For the case of unlicensed spectrum used as a complement to the licensedspectrum, devices connect in the licensed spectrum (e.g., via a primarycell (PCell)) and use carrier aggregation (CA) to benefit fromadditional transmission capacity in the unlicensed spectrum (e.g., via asecondary cell (SCell)). The CA framework allows a device to aggregatetwo or more carriers, with the condition that at least one carrier (orfrequency channel) is in the licensed spectrum and at least one carrieris in the unlicensed spectrum. In the standalone (or completelyunlicensed spectrum) mode of operation, one or more carriers areselected solely in the unlicensed spectrum.

Regulatory requirements, however, may not permit transmissions in theunlicensed spectrum without prior channel sensing, transmission powerlimitations, and/or imposed maximum channel occupancy time. Since theunlicensed spectrum must be shared with other radios of similar ordissimilar wireless technologies, a so-called listen-before-talk (LBT)method needs to be applied. LBT involves sensing the medium for apre-defined minimum amount of time and backing off if the channel isbusy. Due to the centralized coordination and dependency of terminaldevices on the base-station (e.g., evolved NodeB (eNB)) for channelaccess in LTE operation, and imposed LBT regulations, LTE uplink (UL)performance is especially hampered. UL transmission is becoming more andmore important with user-centric applications and the need for pushingdata to cloud.

Today, the unlicensed 5 GHz spectrum is mainly used by equipmentimplementing the Institute of Electrical and Electronics Engineers(IEEE) 802.11 Wireless Local Area Network (WLAN) standard. This standardis known under its marketing brand “Wi-Fi” and allows completelystandalone operation in the unlicensed spectrum. Unlike in LTE, Wi-Fiterminals can asynchronously access the medium and thus show better ULperformance characteristics, especially in congested network conditions.

LTE uses Orthogonal Frequency Division Multiplexing (OFDM) in thedownlink (DL) and Discrete Fourier Transform (DFT)-spread OFDM (alsoreferred to as Single-Carrier Frequency Division Multiple Access(SC-FDMA)) in the UL.

FIG. 1 illustrates an example LTE DL physical resource. As shown in FIG.1 , the basic LTE DL physical resource can be seen as a time-frequencygrid where each resource element (e.g., resource element 10) correspondsto one OFDM subcarrier during one OFDM symbol interval. The UL subframehas the same subcarrier spacing as the DL, and the same number ofSC-FDMA symbols in the time domain as OFDM symbols in the DL.

FIG. 2 illustrates an example of the LTE time-domain structure. In thetime domain, LTE DL transmissions are organized into radio frames (suchas radio frame 20) of 10 ms. Each radio frame 20 consists of tenequally-sized subframes of length T_(subframe)=1 ms, as shown in FIG. 2. Each subframe comprises two slots of duration 0.5 ms each, and theslot numbering within a frame ranges from 0 to 19. For normal cyclicprefix, one subframe consists of 14 OFDM symbols. The duration of eachsymbol is approximately 71.4 μs.

The resource allocation in LTE is typically described in terms ofresource blocks, where a resource block corresponds to one slot (0.5 ms)in the time domain and 12 contiguous subcarriers in the frequencydomain. A pair of two adjacent resource blocks in the time direction(i.e., 1.0 ms) is known as a resource block pair. Resource blocks arenumbered in the frequency domain, starting with 0 from one end of thesystem bandwidth.

DL transmissions are dynamically scheduled (i.e., in each subframe thebase station transmits control information about which terminals data istransmitted to and upon which resource blocks the data is transmitted,in the current DL subframe). This control signaling is typicallytransmitted in the first 1, 2, 3 or 4 OFDM symbols in each subframe andthe number n=1, 2, 3 or 4 is known as the Control Format Indicator(CFI). The DL subframe also contains common reference symbols, which areknown to the receiver and used for coherent demodulation of, forexample, the control information.

FIG. 3 illustrates an example DL subframe. More particularly, FIG. 3illustrates a DL system with CFI=3 OFDM symbols as control. In theexample of FIG. 3, the reference symbols shown are the cell specificreference symbols (CRS), which are used to support multiple functions,including fine-time and frequency synchronization and channel estimationfor certain transmission modes.

UL transmissions are dynamically scheduled (i.e., in each DL subframethe base station transmits control information about which terminalsshould transmit data to the base station in subsequent subframes, andupon which resource blocks the data should be transmitted). The ULresource grid is comprised of data and UL control information in thePhysical Uplink Shared Channel (PUSCH), UL control information in thePhysical Uplink Control Channel (PUCCH), and various reference signalssuch as demodulation reference signals (DMRS) and sounding referencesignals (SRS). DMRS are used for coherent demodulation of PUSCH andPUCCH data, whereas SRS is not associated with any data or controlinformation but is generally used to estimate the UL channel quality forpurposes of frequency-selective scheduling.

FIG. 4 illustrates an example UL subframe. Note that UL DMRS and SRS aretime-multiplexed into the UL subframe, and SRS are always transmitted inthe last symbol of a normal UL subframe. The PUSCH DMRS is transmittedonce every slot for subframes with normal cyclic prefix, and is locatedin the fourth and eleventh SC-FDMA symbols.

From LTE Release 11 onwards, DL or UL resource assignments can also bescheduled on the Enhanced Physical Downlink Control Channel (EPDCCH).For Release 8 to Release 10, only the Physical Downlink Control Channel(PDCCH) is available. Resource grants are user equipment (UE)-specific,and are indicated by scrambling the Downlink Control Information (DCI)Cyclic Redundancy Check (CRC) with the UE-specific Cell Radio NetworkTemporary Identifier (C-RNTI) identifier. A unique C-RNTI is assigned bya cell to every UE associated with it, and can take values in the range0001-FFF3 in hexadecimal format. A UE uses the same C-RNTI on allserving cells.

In LTE, the UL access is typically controlled by the eNB (i.e.,scheduled). In this case, the UE would report to the eNB when data isavailable to be transmitted, for example by sending a Scheduling Request(SR) message. Based on this, the eNB would grant the resources andrelevant information to the UE in order to carry out the transmission ofa certain size of data. The assigned resources are not necessarilysufficient for the UE to transmit all the available data. In such acase, the UE may send a buffer status report (BSR) control message inthe granted resources to inform the eNB about the correct size andupdated size of the data waiting for transmission. Based on that, theeNB would further grant the resources to carry on with the UE ULtransmission of the corrected size of data.

More particularly, every time new data arrives at the UE's empty buffer,the following procedure should be performed. Using the PUCCH, the UEinforms the network that it needs to transmit data by sending a SRindicating that it needs UL access. The UE has a periodic timeslot forSR transmissions (typically on a 5, 10, or 20 ms interval). Once the eNBreceives the SR request bit, it responds with a small “UL grant” that isjust large enough to communicate the size of the pending buffer. Thereaction to this request typically takes 3 ms. After the UE receives andprocesses its first UL grant (which takes about 3 ms), the UE typicallysends a BSR, which is a Medium Access Control (MAC) Control Element (CE)used to provide information about the amount of pending data in the ULbuffer of the UE. If the grant is big enough, the UE sends data from itsbuffer within this transmission as well. Whether the BSR is sent alsodepends on conditions specified in 3GPP TS 36.321 v12.1.0 (2014-03),“3rd Generation Partnership Project; Technical Specification Group RadioAccess Network; Evolved Universal Terrestrial Radio Access (E-UTRA);Medium Access Control (MAC) protocol specification,” Release 12. The eNBreceives the BSR message, allocates the necessary UL resources, andsends back another UL grant that will allow the device to drain itsbuffer.

In total, about 16 ms (plus time to wait for a PUCCH transmissionopportunity) of delay can be expected between data arrival at the emptybuffer in the UE and the reception of this data in the eNB.

In case the UE is not Radio Resource Control (RRC) connected in LTE, orhas lost its UL synchronization since it did not transmit or receiveanything for a certain time, the UE would use the random access (RA)procedure to connect to the network, obtain synchronization, and alsosend the SR. If this is the case, the procedure until the data can besent would take even longer than the SR transmission on PUCCH.

In the LTE system, the transmission formats and parameters arecontrolled by the eNB. Typically, the DCI contains: resources allocatedfor UL transmission (including whether frequency hopping is applied);modulation and coding scheme; redundancy versions; new data indicator;transmit power control command; information about DMRS; the targetcarrier index (in cases of cross-carrier scheduling); and otherapplicable control information on UL transmissions. The DCI is firstprotected by 16-bit CRC. The CRC bits are further scrambled by theassigned UE identity (e.g., C-RNTI). The DCI and scrambled CRC bits arefurther protected by convolutional coding. The encoded bits aretransmitted from the eNB to UE using either PDCCH or EPDCCH.

Semi-Persistent Scheduling (SPS) is similar to pre-scheduling in thatthe UE modem is granted radio resources periodically. The maindifference is that there is no explicit grant signal sent every time theUE modem is granted resources. Instead, the eNB sends a long-lastinggrant that allows the UE modem to keep track of when it is grantedresources and use that time/frequency slot for sending data.

Instant Uplink Access (IUA) was discussed in the 3GPP latency reductionstudy item. IUA is a form of pre-scheduling to allow transmission ofdata without explicit SRs. IUA is an enhancement of the SPS frameworkthat introduces a new UE condition: “Do not transmit using the grantunless there is data in buffer.”

In the current LTE framework, a UE with an UL grant is forced to sendsomething. Even if the UE has no UL data, the UE would send padding. Inaddition, the lowest SPS period is 10 subframes. With fast UL, twomodifications are done to SPS to enable IUA. First, it allows an SPSperiod down to 1 subframe (or transmission time interval (TTI)). Second,it allows a skip-padding configuration (i.e., the UE does not need totransmit in the granted UL resources if it does not have data for thatsubframe).

In the current LTE specifications, the SPS and IUA features are definedonly for the primary cell (PCell). The configuration and commands of SPSand IUA are also defined and performed on a per-UE basis.

In typical deployments of WLANs, carrier sense multiple access withcollision avoidance (CSMA/CA) is used for medium access. This means thatthe channel is sensed to perform a Clear Channel Assessment (CCA), and atransmission is initiated only if the channel is declared Idle. If thechannel is declared Busy, the transmission is essentially deferred untilthe channel is deemed to be Idle.

FIG. 5 illustrates an example of the LBT mechanism in Wi-Fi. After aWi-Fi station A transmits a data frame to a station B, station Btransmits the acknowledgement (ACK) frame back to station A with a delayof 16 μs. The ACK frame is transmitted by station B without performing alisten-before-talk (LBT) operation. To prevent another stationinterfering with such an ACK frame transmission, a station shall deferfor a duration of 34 μs (referred to as Distributed Inter-frame Space(DIFS)) after the channel is observed to be occupied before assessingagain whether the channel is occupied. Thus, a station that wishes totransmit first performs a CCA by sensing the medium for a fixed durationDIFS. If the medium is idle, then the station assumes that it may takeownership of the medium and begin a frame exchange sequence. If themedium is busy, the station waits for the medium to go idle, defers forDIFS, and waits for a further random backoff period.

In the basic protocol described above, when the medium becomes availablemultiple Wi-Fi stations may be ready to transmit. This can result incollision. To reduce collisions, stations intending to transmit select arandom backoff counter and defer for that number of slot channel idletimes. The random backoff counter is selected as a random integer drawnfrom a uniform distribution over the interval of [0, CW]. The defaultsize of the random backoff contention window, CWmin, is set in the IEEEspecifications. Note that collisions can still occur even under thisrandom backoff protocol, for example when there are many stationscontending for channel access. Hence, to avoid recurring collisions, thebackoff contention window size CW is doubled whenever the stationdetects a collision of its transmission up to a limit, CWmax, also setin the IEEE specifications. When a station succeeds in a transmissionwithout collision, it resets its random backoff contention window sizeback to the default value CWmin.

FIG. 6 illustrates an example of LBT in European TelecommunicationsStandards Institute (ETSI) EN 301.893. For a device not utilizing theWi-Fi protocol, the ETSI standard EN 301.893, v1.7.1 provides thefollowing requirements and minimum behavior for the load-based CCA.

A first requirement is that before a transmission or a burst oftransmissions on an Operating Channel, the equipment shall perform aClear Channel Assessment (CCA) check using “energy detect.” Theequipment shall observe the Operating Channel(s) for the duration of theCCA observation time which shall be not less than 20 μs. The CCAobservation time used by the equipment shall be declared by themanufacturer. The Operating Channel shall be considered occupied if theenergy level in the channel exceeds the threshold corresponding to thepower level given in the fifth requirement described below. If theequipment finds the channel to be clear, it may transmit immediately(see the third requirement described below). This is shown in theexample of FIG. 6 at time intervals 1 and 2. At time interval 1, theequipment performs a CCA check as described above. Having found thechannel to be clear, the equipment transmits immediately during timeinterval 2.

A second requirement is that if the equipment finds an Operating Channeloccupied, it shall not transmit in that channel. The equipment shallperform an Extended CCA check in which the Operating Channel is observedfor the duration of a random factor N multiplied by the CCA observationtime. N defines the number of clear idle slots resulting in a total IdlePeriod that need to be observed before initiation of the transmission.The value of N shall be randomly selected in the range 1 . . . q everytime an Extended CCA is required and the value stored in a counter. Thevalue of q is selected by the manufacturer in the range 4 . . . 32. Thisselected value shall be declared by the manufacturer (see clause 5.3.1q)). The counter is decremented every time a CCA slot is considered tobe “unoccupied”. When the counter reaches zero, the equipment maytransmit.

This is shown in the example of FIG. 6 at time interval 3. At thebeginning of time interval 3, the equipment performs a CCA check andfinds that the channel is occupied. Thus, the equipment performs anExtended CCA check as described above. In the example of FIG. 6 , thevalue of N is initialized by N=3. The counter N is decremented everytime a CCA slot is considered to be unoccupied. In the example of FIG. 6, the first channel CCA slot in the Extended CCA check is determined tobe unoccupied, so the counter is decremented from 3 to 2. The secondchannel CCA slot in the Extended CCA check is determined to be occupied,so the counter is not decremented from 2. The third channel CCA slot inthe Extended CCA check is determined to be unoccupied, so the counter isdecremented from 2 to 1. Similarly, the fourth channel CCA slot in theExtended CCA check is determined to be unoccupied, so the counter isdecremented from 1 to 0. When the counter reaches zero, the equipmenttransmits during time interval 4.

A third requirement is that the total time that an equipment makes useof an Operating Channel is the Maximum Channel Occupancy Time whichshall be less than (13/32)×q ms, with q as defined in the secondrequirement described above, after which the device shall perform theExtended CCA described in the second requirement above.

A fourth requirement is that the equipment, upon correct reception of apacket which was intended for this equipment, can skip CCA andimmediately proceed with the transmission of management and controlframes (e.g., ACK and Block ACK frames). This is shown in the example ofFIG. 6 during time interval 5. A consecutive sequence of transmissionsby the equipment, without it performing a new CCA, shall not exceed theMaximum Channel Occupancy Time as defined in the third requirementdescribed above. For the purpose of multi-cast, the ACK transmissions(associated with the same data packet) of the individual devices areallowed to take place in a sequence.

A fifth requirement is that the energy detection threshold for the CCAshall be proportional to the maximum transmit power (PH) of thetransmitter. For a 23 dBm e.i.r.p. transmitter, the CCA threshold level(TL) shall be equal or lower than −73 dBm/MHz at the input to thereceiver (assuming a 0 dBi receive antenna). For other transmit powerlevels, the CCA threshold level TL shall be calculated using theformula: TL=−73 dBm/MHz+23−PH (assuming a 0 dBi receive antenna and PHspecified in dBm e.i.r.p.).

Up to now, the spectrum used by LTE is dedicated to LTE. This has theadvantage that the LTE system does not need to care about thecoexistence issue. It also allows spectrum efficiency to be maximized.The spectrum allocated to LTE is limited, however, and cannot meet theever-increasing demand for larger throughput from applications and/orservices. Therefore, Release 13 LAA extended LTE to exploit unlicensedspectrum in addition to licensed spectrum. Unlicensed spectrum can, bydefinition, be simultaneously used by multiple different technologies.LTE therefore needs to consider the coexistence issue with other systemssuch as IEEE 802.11 (Wi-Fi). Operating LTE in the same manner inunlicensed spectrum as in licensed spectrum can seriously degrade theperformance of Wi-Fi, as Wi-Fi will not transmit once it detects thechannel is occupied.

FIG. 7 illustrates an example of LAA to unlicensed spectrum using LTEcarrier aggregation. One way to utilize the unlicensed spectrum reliablyis to transmit essential control signals and channels on a licensedcarrier. That is, as shown in FIG. 7 , a wireless device 110 (e.g., aUE) is connected to a PCell 705 in the licensed band and one or moresecondary cells (SCells) 710 in the unlicensed band. As used herein, asecondary cell in unlicensed spectrum is referred to as a LAA secondarycell (LAA SCell). In the case of standalone operation (as in MulteFire),no licensed cell is available for UL control signal transmissions.

The combination of the LBT and maximum transmission burst durationfunctionalities of LAA/MulteFire implies that LTE reference signals arenot guaranteed to be transmitted with a fixed periodicity. To supportsynchronization, frequency estimation, and radio resource management(RRM) measurements, the discovery reference signal/subframe (DRS) isperiodically transmitted and contains the Primary Synchronization Signal(PSS), Secondary Synchronization Signal (SSS), Cell-Specific ReferenceSignal (CRS), and Channel State Information Reference Signal (CSI-RS)for LAA, and also the Physical Broadcast Channel (PBCH) and SessionInformation Block (SIB) transmission for MulteFire. Due to LBTconstraints, DRS transmission cannot be guaranteed in a particular timeinstance. Hence, the DRS can be transmitted within a window specified bythe DRS Measurement Time Configuration (DMTC).

SUMMARY

To address problems with existing approaches, disclosed is a method in awireless device. The method comprises obtaining information related to asignal transmission configuration for autonomous uplink transmission bythe wireless device, the information comprising: a set of pre-allocatedresources for use by the wireless device in performing autonomous uplinktransmission on at least one secondary cell established between thewireless device and a network node; and a periodicity associated withthe set of pre-allocated resources. The method comprises performingautonomous uplink transmission according to the obtained informationrelated to the signal transmission configuration.

In certain embodiments, the information related to the signaltransmission configuration for autonomous uplink transmission by thewireless device may further comprise information about one or moresubframes that should be avoided by the wireless device when performingautonomous uplink transmission. In certain embodiments, the informationabout one or more subframes that should be avoided by the wirelessdevice when performing autonomous uplink transmission may comprise oneor more of: an indication of a subframe that the network node uses totransmit a discovery reference signal and that the wireless deviceshould avoid; and an indication of a subframe immediately preceding thesubframe that the network node uses to transmit the discovery referencesignal and that the wireless device should avoid.

In certain embodiments, the information about one or more subframes thatshould be avoided by the wireless device when performing autonomousuplink transmission may comprise one or more of: an indication of allsubframes within a discovery reference signal measurement timingconfiguration window and that the wireless device should avoid; anindication of a subframe immediately preceding the discovery referencesignal measurement timing configuration window and that the wirelessdevice should avoid; and an indication of the subframes within thediscovery reference signal measurement timing configuration window andof the subframe immediately preceding the discovery reference signalmeasurement timing configuration window and that the wireless deviceshould avoid until the wireless device receives a discovery referencesignal.

In certain embodiments, the information about one or more subframes thatshould be avoided by the wireless device when performing autonomousuplink transmission may comprise an indication of one or more subframesconfigured as measurement gaps, and that the wireless device shouldavoid. In certain embodiments, the information about one or moresubframes that should be avoided by the wireless device when performingautonomous uplink transmission may comprise an indication of one or moresubframes between reception of a first trigger and a second trigger whena two-stage grant is used by the network node to allocate resources tothe wireless device, and that the wireless device should avoid.

In certain embodiments, obtaining information related to the signaltransmission configuration for autonomous uplink transmission by thewireless device may comprise receiving an indication of a subframepattern applicable to autonomous uplink transmission by the wirelessdevice. The indication of the subframe pattern may be a bitmap.

In certain embodiments, the information related to the signaltransmission configuration for autonomous uplink transmission by thewireless device may comprise one or more of an offset value fordetermining a length of a sensing duration to be used by the wirelessdevice before a next allowed transmission period; and a rotationperiodicity. The method may comprise receiving at least one of theoffset value and the rotation periodicity via one or more of: a commonphysical downlink control channel; and higher layer signaling. Theoffset value may correspond to a priority level of the wireless devicefor performing autonomous uplink transmissions.

In certain embodiments, the method may comprise receiving an indicationthat the wireless device should deactivate autonomous uplinktransmission. In certain embodiments, the method may comprise receivingan indication that the wireless device should activate autonomous uplinktransmission. One or more of the indication that the wireless deviceshould deactivate autonomous uplink transmission and the indication thatthe wireless device should activate autonomous uplink transmission maybe received over one or more of: broadcast-type control signaling; anddedicated control signaling.

In certain embodiments, the at least one secondary cell establishedbetween the wireless device and the network node may be in unlicensedspectrum.

Also disclosed is a wireless device. The wireless device comprisesprocessing circuitry. The processing circuitry is configured to obtaininformation related to a signal transmission configuration forautonomous uplink transmission by the wireless device, the informationcomprising: a set of pre-allocated resources for use by the wirelessdevice in performing autonomous uplink transmission on at least onesecondary cell established between the wireless device and a networknode; and a periodicity associated with the set of pre-allocatedresources. The processing circuitry is configured to perform autonomousuplink transmission according to the obtained information related to thesignal transmission configuration.

Also disclosed is a wireless device. The wireless device comprises areceiving module, a determining module, and a communication module. Thedetermining module is configured to obtain information related to asignal transmission configuration for autonomous uplink transmission bythe wireless device, the information comprising: a set of pre-allocatedresources for use by the wireless device in performing autonomous uplinktransmission on at least one secondary cell established between thewireless device and a network node; and a periodicity associated withthe set of pre-allocated resources. The communication module isconfigured to perform autonomous uplink transmission according to theobtained information related to the signal transmission configuration.

Also disclosed is a method in a network node. The method comprisesdetermining information related to a signal transmission configurationfor autonomous uplink transmission by a wireless device, the informationcomprising: a set of pre-allocated resources for use by the wirelessdevice in performing autonomous uplink transmission on at least onesecondary cell established between the network node and the wirelessdevice; and a periodicity associated with the set of pre-allocatedresources. The method comprises configuring the wireless device toperform autonomous uplink transmission according to the determinedinformation related to the signal transmission configuration.

In certain embodiments, the information related to the signaltransmission configuration for autonomous uplink transmission by thewireless device may further comprise information about one or moresubframes that should be avoided by the wireless device when performingautonomous uplink transmission. In certain embodiments, the one or moresubframes that should be avoided by the wireless device when performingautonomous uplink transmission may comprise one or more of a subframethat the network node uses to transmit a discovery reference signal; anda subframe immediately preceding the subframe that the network node usesto transmit the discovery reference signal.

In certain embodiments, the one or more subframes that should be avoidedby the wireless device when performing autonomous uplink transmissionmay comprise one or more of all subframes within a discovery referencesignal measurement timing configuration window; a subframe immediatelypreceding the discovery reference signal measurement timingconfiguration window; and the subframes within the discovery referencesignal measurement timing configuration window and the subframeimmediately preceding the discovery reference signal measurement timingconfiguration window until the wireless device receives a discoveryreference signal.

In certain embodiments, the one or more subframes that should be avoidedby the wireless device when performing autonomous uplink transmissionmay comprise one or more subframes configured as measurement gaps.

In certain embodiments, the one or more subframes that should be avoidedby the wireless device when performing autonomous uplink transmissionmay comprise one or more subframes between reception of a first triggerand a second trigger when a two-stage grant is used by the network nodeto allocate resources to the wireless device.

In certain embodiments, configuring the wireless device to performautonomous uplink transmission according to the determined informationrelated to the signal transmission configuration may comprise sendingthe determined information related to the signal transmissionconfiguration to the wireless device.

In certain embodiments, configuring the wireless device to performautonomous uplink transmission according to the determined informationrelated to the signal transmission configuration may comprise sending anindication of a subframe pattern applicable to autonomous uplinktransmission by the wireless device. In certain embodiments, theindication of the subframe pattern may be a bitmap.

In certain embodiments, the information related to the signaltransmission configuration for autonomous uplink transmission by thewireless device may comprise one or more of an offset value fordetermining a length of a sensing duration to be used by the wirelessdevice before a next allowed transmission period; and a rotationperiodicity. The method may comprise sending at least one of the offsetvalue and the rotation periodicity to the wireless device via one ormore of: a common physical downlink control channel; and higher layersignaling. The offset value may correspond to a priority level of thewireless device for performing autonomous uplink transmissions.

In certain embodiments, the method may comprise: determining, based onone or more criteria, that the wireless device should deactivateautonomous uplink transmission and switch to schedule-based access; andsending, to the wireless device, an indication that the wireless deviceshould deactivate autonomous uplink transmission. The one or morecriteria may comprise one or more of a buffer status at the networknode; a traffic type; a buffer build-up; a cleanliness of the channel; anumber of UEs with non-empty UL buffer; a Negative Acknowledgement(NACK) to ACK ratio for one or more wireless devices; and a number ofcollisions on a channel where multiple wireless devices attempt toaccess the channel at the same time. In certain embodiments, the methodmay comprise: determining that the wireless device should switch fromscheduled-based access to autonomous uplink transmission; and sending,to the wireless device, an indication that the wireless device shouldactivate autonomous uplink transmission. In certain embodiments, one ormore of the indication that the wireless device should deactivateautonomous uplink transmission and the indication that the wirelessdevice should activate autonomous uplink transmission are sent using oneor more of: broadcast-type control signaling; and dedicated controlsignaling.

In certain embodiments, the at least one secondary cell establishedbetween the network node and the wireless device may be in unlicensedspectrum.

Also disclosed is a network node. The network node comprises processingcircuitry. The processing circuitry is configured to determineinformation related to a signal transmission configuration forautonomous uplink transmission by a wireless device, the informationcomprising: a set of pre-allocated resources for use by the wirelessdevice in performing autonomous uplink transmission on at least onesecondary cell established between the network node and the wirelessdevice; and a periodicity associated with the set of pre-allocatedresources. The processing circuitry is configured to configure thewireless device to perform autonomous uplink transmission according tothe determined information related to the signal transmissionconfiguration.

Also disclosed is a network node. The network node comprises acommunication module, a receiving module, and a determining module. Thedetermining module is configured to determine information related to asignal transmission configuration for autonomous uplink transmission bya wireless device, the information comprising: a set of pre-allocatedresources for use by the wireless device in performing autonomous uplinktransmission on at least one secondary cell established between thenetwork node and the wireless device; and a periodicity associated withthe set of pre-allocated resources. The determining module is configuredto configure the wireless device to perform autonomous uplinktransmission according to the determined information related to thesignal transmission configuration.

Certain embodiments of the present disclosure may provide one or moretechnical advantages. For example, certain embodiments mayadvantageously allow the LTE system to enhance its UL channel access,especially in unlicensed spectrum. As another example, certainembodiments may advantageously reduce UL latency at low-load conditionsand increase the channel utilization for UL access. As still anotherexample, certain embodiments may advantageously reduce contention on theunlicensed channel in loaded situations. As yet another example, certainembodiments may improve efficiency of LTE in the unlicensed spectrum,which in turn may benefit and support spectral coexistence with othercollocated networks. Other advantages may be readily apparent to onehaving skill in the art. Certain embodiments may have none, some, or allof the recited advantages.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the disclosed embodiments and theirfeatures and advantages, reference is now made to the followingdescription, taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 illustrates an example LTE DL physical resource;

FIG. 2 illustrates an example of the LTE time-domain structure;

FIG. 3 illustrates an example DL subframe;

FIG. 4 illustrates an example UL subframe;

FIG. 5 illustrates an example of the LBT mechanism in Wi-Fi;

FIG. 6 illustrates an example of LBT in ETSI EN 301.893;

FIG. 7 illustrates an example of LAA to unlicensed spectrum using LTEcarrier aggregation;

FIG. 8 illustrates an exemplary wireless communications network, inaccordance with certain embodiments;

FIG. 9 is a signal flow diagram, in accordance with certain embodiments;

FIG. 10 is a flow diagram of a method in a wireless device, inaccordance with certain embodiments;

FIG. 11 is a flow diagram of a method in a network node, in accordancewith certain embodiments;

FIG. 12 is a block schematic of an exemplary wireless device, inaccordance with certain embodiments;

FIG. 13 is a block schematic of an exemplary network node, in accordancewith certain embodiments;

FIG. 14 is a block schematic of an exemplary radio network controller orcore network node, in accordance with certain embodiments;

FIG. 15 is a block schematic of an exemplary wireless device, inaccordance with certain embodiments; and

FIG. 16 is a block schematic of an exemplary network node, in accordancewith certain embodiments.

DETAILED DESCRIPTION

For LTE UL channel access, both the wireless device (e.g., a UE) and thenetwork node (e.g., an eNB) need to perform LBT operations correspondingto the SR, scheduling grant and data transmission phases. In contrast,Wi-Fi terminals only need to perform LBT once in the UL datatransmission phase. Furthermore, Wi-Fi terminals can asynchronously senddata compared to the synchronized LTE system. Thus, Wi-Fi terminals havea natural advantage over LTE terminals in UL data transmission, and showsuperior performance in collocated deployment scenarios according tosimulation studies.

Overall study results show that Wi-Fi has a better UL performance thanLTE, particularly in low-load or less congested network conditions. Asthe network congestion or load is increased, the LTE channel accessmechanism (Time Division Multiple Access (TDMA)-type) becomes moreefficient, but Wi-Fi UL performance is still superior. Two different ULconcepts for LTE/LAA/MulteFire have been proposed to increase theflexibility and the performance of UL. According to a first concept,similar to Wi-Fi behavior, a wireless device can start the ULtransmission without waiting for permission from the network node. Inother words, a wireless device can perform LBT to gain UL channel accesswhenever the UL data arrives, without transmitting a SR or having an ULgrant from the network node. The wireless device can use the unscheduledmode for the whole data transmission or, alternatively, transmit usingunscheduled mode for the first N transmission bursts and then switchback to the network node-controlled scheduling mode. According to asecond concept, SPS grants with granted periodicity down to 1 ms areproposed to achieve similar behavior as autonomous UL. With aperiodicity of 1 ms, a wireless device can attempt to transmit everysubframe for the whole granted period.

Nonetheless, at high load autonomous UL transmission can lead to a highnumber of collisions and longer deferring. In such a scenario, it isbeneficial that the network node gradually adapt its behavior fromunscheduled autonomous-based UL access towards schedule-based access.

The present disclosure contemplates various embodiments that may addressthese and other deficiencies associated with existing approaches. Forexample, in certain embodiments methods for avoiding collisions duringautonomous transmissions are disclosed. In certain embodiments, awireless device is configured to avoid specific subframes whenperforming autonomous UL transmission. In certain embodiments, aligningthe starting point of the transmissions from different wireless devicesis avoided, for example by giving rotating priority to starttransmission in different subframes among wireless devices configuredwith autonomous UL transmission. In certain embodiments, the UL accessis adapted from unscheduled autonomous transmission to schedule-basedaccess (and vice versa) in LAA and/or standalone LTE. In some cases, thedynamic switching between scheduled and unscheduled UL access may bebased on the load situation. Employing one or more of these proceduresmay advantageously improve the UL performance in LAA or stand-alone LTEby avoiding collisions among wireless devices.

According to one example embodiment, a method in a wireless device isdisclosed. The wireless device obtains information related to a signaltransmission configuration for autonomous UL transmission by thewireless device. The information may comprise: a set of pre-allocatedresources for use by the wireless device in performing autonomous ULtransmission on at least one secondary cell established between thewireless device and a network node; and a periodicity associated withthe set of pre-allocated resources. The wireless device may obtain theinformation related to the signal transmission configuration forautonomous UL transmission in any suitable manner. For example, thewireless device may receive the information related to the signaltransmission configuration from a network node (e.g., an eNB). Asanother example, the wireless device may determine the informationrelated to the signal transmission configuration autonomously.

The wireless device performs autonomous UL transmission according to theobtained information related to the signal transmission configuration.In certain embodiments, the information related to the signaltransmission configuration for autonomous UL transmission by thewireless device may further comprise information about one or moresubframes that should be avoided by the wireless device when performingautonomous UL transmission. In such a scenario, the wireless device mayavoid one or more subframes when performing autonomous UL transmissionbased on the information about the one or more subframes that should beavoided.

According to another example embodiment, a method in a network node(e.g., an eNB) is disclosed. The network node determines informationrelated to a signal transmission configuration for autonomous ULtransmission by a wireless device. The information may comprise: a setof pre-allocated resources for use by the wireless device in performingautonomous UL transmission on at least one secondary cell establishedbetween the network node and the wireless device; and a periodicityassociated with the set of pre-allocated resources. In certainembodiments, the information related to the signal transmissionconfiguration for autonomous UL transmission by the wireless device mayfurther comprise information about one or more subframes that should beavoided by the wireless device when performing autonomous ULtransmission. The network node configures the wireless device to performautonomous UL transmission according to the determined informationrelated to the signal transmission configuration.

Certain embodiments of the present disclosure may provide one or moretechnical advantages. For example, certain embodiments mayadvantageously allow the LTE system to enhance its UL channel access,especially in unlicensed spectrum. As another example, certainembodiments may advantageously reduce UL latency at low-load conditionsand increase the channel utilization for UL access. As still anotherexample, certain embodiments may reduce contention on the unlicensedchannel in loaded situations. As yet another example, certainembodiments may improve efficiency of LTE in the unlicensed spectrum,which in turn may benefit and support spectral coexistence with othercollocated networks, such as Wi-Fi and other LTE in unlicensed spectrum(LTE-U, LAA and/or standalone LTE) networks. Other advantages may bereadily apparent to one having skill in the art. Certain embodiments mayhave none, some, or all of the recited advantages.

FIG. 8 is a block diagram illustrating an embodiment of a network 100,in accordance with certain embodiments. Network 100 includes one or morewireless devices 110 (e.g., a UE) and one or more network node(s) 115(e.g., an eNB). Wireless devices 110 may communicate with network nodes115 over a wireless interface. For example, a wireless device 110 maytransmit wireless signals to one or more of network nodes 115, and/orreceive wireless signals from one or more of network nodes 115. Thewireless signals may contain voice traffic, data traffic, controlsignals, and/or any other suitable information. In some embodiments, anarea of wireless signal coverage associated with a network node 115 maybe referred to as a cell 125. Wireless devices 110 may be capable ofperforming LAA and CA operations, and may be capable of operating inboth the licensed and unlicensed spectrum. In some embodiments, wirelessdevices 110 may have device-to-device (D2D) capability. Thus, wirelessdevices 110 may be able to receive signals from and/or transmit signalsdirectly to another wireless device.

In certain embodiments, network nodes 115 may interface with a radionetwork controller. The radio network controller may control networknodes 115 and may provide certain radio resource management functions,mobility management functions, and/or other suitable functions. Incertain embodiments, the functions of the radio network controller maybe included in network node 115. The radio network controller mayinterface with a core network node. In certain embodiments, the radionetwork controller may interface with the core network node via aninterconnecting network 120. Interconnecting network 120 may refer toany interconnecting system capable of transmitting audio, video,signals, data, messages, or any combination of the preceding.Interconnecting network 120 may include all or a portion of a publicswitched telephone network (PSTN), a public or private data network, alocal area network (LAN), a metropolitan area network (MAN), a wide areanetwork (WAN), a local, regional, or global communication or computernetwork such as the Internet, a wireline or wireless network, anenterprise intranet, or any other suitable communication link, includingcombinations thereof.

In some embodiments, the core network node may manage the establishmentof communication sessions and various other functionalities for wirelessdevices 110. Wireless devices 110 may exchange certain signals with thecore network node using the non-access stratum layer. In non-accessstratum signaling, signals between wireless devices 110 and the corenetwork node may be transparently passed through the radio accessnetwork. In certain embodiments, network nodes 115 may interface withone or more network nodes over an internode interface, such as, forexample, an X2 interface.

As described above, example embodiments of network 100 may include oneor more wireless devices 110, and one or more different types of networknodes capable of communicating (directly or indirectly) with wirelessdevices 110.

In some embodiments, the non-limiting term wireless device is used.Wireless devices 110 described herein can be any type of wireless devicecapable, configured, arranged and/or operable to communicate wirelesslywith network nodes 115 and/or another wireless device. Communicatingwirelessly may involve transmitting and/or receiving wireless signalsusing electromagnetic signals, radio waves, infrared signals, and/orother types of signals suitable for conveying information through air.In particular embodiments, wireless devices 110 may be configured totransmit and/or receive information without direct human interaction.For instance, a wireless device 110 may be designed to transmitinformation to a network on a predetermined schedule, when triggered byan internal or external event, or in response to requests from thenetwork. Generally, a wireless device 110 may represent any devicecapable of, configured for, arranged for, and/or operable for wirelesscommunication, for example radio communication devices. Examples ofwireless devices 110 include, but are not limited to, UEs such as smartphones. Further examples include wireless cameras, wireless-enabledtablet computers, mobile terminals, laptop-embedded equipment (LEE),laptop-mounted equipment (LME), USB dongles, and/or wirelesscustomer-premises equipment (CPE). Wireless device 110 may also be aradio communication device, target device, D2D UE,machine-type-communication (MTC) UE or UE capable of machine-to-machine(M2M) communication, low-cost and/or low-complexity UE, a sensorequipped with UE, or any other suitable devices. Wireless devices 110may operate under either normal coverage or enhanced coverage withrespect to its serving cell. The enhanced coverage may beinterchangeably referred to as extended coverage. UE 110 may alsooperate in a plurality of coverage levels (e.g., normal coverage,enhanced coverage level 1, enhanced coverage level 2, enhanced coveragelevel 3 and so on). In some cases, UE 110 may also operate inout-of-coverage scenarios.

As one specific example, wireless device 110 may represent a UEconfigured for communication in accordance with one or morecommunication standards promulgated by 3GPP, such as 3GPP's GSM, UMTS,LTE, and/or 5G standards. As used herein, a “UE” may not necessarilyhave a “user” in the sense of a human user who owns and/or operates therelevant device. Instead, a UE may represent a device that is intendedfor sale to, or operation by, a human user but that may not initially beassociated with a specific human user.

Wireless devices 110 may support D2D communication, for example byimplementing a 3GPP standard for sidelink communication, and may in thiscase be referred to as a D2D communication device.

As yet another specific example, in an Internet of Things (TOT)scenario, a wireless device 110 may represent a machine or other devicethat performs monitoring and/or measurements, and transmits the resultsof such monitoring and/or measurements to another wireless device and/ora network node. The wireless device may in this case be a M2M device,which may in a 3GPP context be referred to as a MTC device. As oneparticular example, a wireless device 110 may be a UE implementing the3GPP narrow band internet of things (NB-IoT) standard. Particularexamples of such machines or devices are sensors, metering devices suchas power meters, industrial machinery, or home or personal appliances(e.g., refrigerators, televisions, personal wearables such as watches,etc.). In other scenarios, a wireless device 110 may represent a vehicleor other equipment that is capable of monitoring and/or reporting on itsoperational status or other functions associated with its operation.

Wireless device 110 as described above may represent the endpoint of awireless connection, in which case the device may be referred to as awireless terminal. Furthermore, a wireless device 110 as described abovemay be mobile, in which case it may also be referred to as a mobiledevice or a mobile terminal.

Also, in some embodiments generic terminology, “network node” is used.As used herein, “network node” refers to equipment capable, configured,arranged and/or operable to communicate directly or indirectly with awireless device and/or with other equipment in the wirelesscommunication network that enable and/or provide wireless access to thewireless device. Examples of network nodes include, but are not limitedto, access points (APs), in particular radio APs. A network node mayrepresent base stations (BSs), such as radio base stations. Particularexamples of radio base stations include Node Bs, evolved Node Bs (eNBs),and gNBs. Base stations may be categorized based on the amount ofcoverage they provide (or, stated differently, their transmit powerlevel) and may then also be referred to as femto base stations, picobase stations, micro base stations, or macro base stations. “Networknode” also includes one or more (or all) parts of a distributed radiobase station such as centralized digital units and/or remote radio units(RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remoteradio units may or may not be integrated with an antenna as an antennaintegrated radio. Parts of a distributed radio base stations may also bereferred to as nodes in a distributed antenna system (DAS).

As a particular non-limiting example, a base station may be a relay nodeor a relay donor node controlling a relay.

Yet further examples of network nodes include multi-standard radio (MSR)radio equipment such as MSR BSs, network controllers such as radionetwork controllers (RNCs) or base station controllers (BSCs), basetransceiver stations (BTSs), transmission points, transmission nodes,Multi-cell/multicast Coordination Entities (MCEs), core network nodes(e.g., MSCs, MMEs, etc.), Operation and Maintenance (O&M) nodes,Operations Support System (OSS) nodes, Self-Organizing Network (SON)nodes, positioning nodes (e.g., Evolved Serving Mobile Location Center(E-SMLCs)), minimization of drive tests (MDTs), or any other suitablenetwork node. More generally, however, network nodes may represent anysuitable device (or group of devices) capable, configured, arranged,and/or operable to enable and/or provide a wireless device access to thewireless communication network or to provide some service to a wirelessdevice that has accessed the wireless communication network.

The terminology such as network node and wireless device should beconsidered non-limiting and does in particular not imply a certainhierarchical relation between the two; in general “network node” couldbe considered as device 1 and “wireless device” device 2, and these twodevices communicate with each other over some radio channel.

Example embodiments of wireless device 110, network nodes 115, and othernetwork nodes (such as radio network controller or core network node)are described in more detail below with respect to FIGS. 12-16 .

Although FIG. 8 illustrates a particular arrangement of network 100, thepresent disclosure contemplates that the various embodiments describedherein may be applied to a variety of networks having any suitableconfiguration. For example, network 100 may include any suitable numberof wireless devices 110 and network nodes 115, as well as any additionalelements suitable to support communication between wireless devices orbetween a wireless device and another communication device (such as alandline telephone). Furthermore, although certain embodiments may bedescribed as implemented in an LTE/MulteFire network, the embodimentsmay be implemented in any appropriate type of telecommunication systemsupporting any suitable communication standards (including 5G standards)and using any suitable components, and are applicable to any radioaccess technology (RAT) or multi-RAT systems in which a wireless devicereceives and/or transmits signals (e.g., data). For example, the variousembodiments described herein may be applicable to LTE, LTE-Advanced, LTEin Unlicensed Spectrum (LTE-U), MulteFire, NR, 5G, IoT, NB-IoT, UMTS,HSPA, GSM, cdma2000, WCDMA, WiMax, UMB, WiFi, another suitable radioaccess technology, or any suitable combination of one or more radioaccess technologies. Although the design of autonomous transmissionsystems with collision avoidance adaptation and related embodiments maybe described herein using the LAA/MulteFire UL as examples, the presentdisclosure is not limited to these examples. Rather, the presentdisclosure contemplates that the various embodiments described hereinmay be applied to other systems as well as DL or sidelinks.

As described above, the present disclosure contemplates variousembodiments that may address certain deficiencies associated withexisting approaches to autonomous UL transmission. In some cases, theSPS/IUA features of the LTE specifications are modified to supporteffective autonomous UL transmission protocol for LAA and MulteFiresystems. For example, in certain embodiments the SPS/IUA features may beextended to the secondary cells. In some cases, wireless devices 110 maybe configured with 1 ms SPS periodicity and allowed to transmit withfull bandwidth. As another example, the SPS periodicity configurationmay be updated on (e)PDCCH/CPDCCH.

In certain embodiments, a wireless device 110 (e.g., wireless device110A) obtains information related to a signal transmission configurationfor autonomous UL transmission by wireless device 110A. The informationrelated to the signal transmission configuration may include a set ofpre-allocated resources for use by wireless device 110A in performingautonomous UL transmission on at least one secondary cell establishedbetween wireless device 110A and a network node 115, such as networknode 115A, as well as a periodicity associated with the set ofpre-allocated resources. Wireless device 110A performs autonomous ULtransmission according to the obtained information related to the signaltransmission configuration.

In certain embodiments, the information related to the signaltransmission configuration for autonomous UL transmission by wirelessdevice 110A includes information about one or more subframes that shouldbe avoided by wireless device 110A when performing autonomous ULtransmission. In some cases, the information related to the signaltransmission configuration for autonomous UL transmission may identifyone or more types of subframes, as well as indicate that wireless device110A should avoid these subframes when performing autonomous ULtransmission. This may advantageously enable wireless device 110A toautomatically avoid specific subframes when it performs autonomous ULtransmission, unlike the existing approach in SPS/IUA.

Wireless device 110A may be configured to avoid any suitable type ofsubframe. As one example, wireless device 110A may avoid a subframe thatnetwork node 115A uses to transmit the DRS. In certain embodiments, thesubframe before the DRS subframe may also be avoided by wireless device110A. As another example, wireless device 110A may avoid all subframeswithin the DMTC window, as well as the subframe before the window. Asstill another example, wireless device 110A may avoid the subframeswithin the DMTC window, as well as the one before the window, until theDRS subframe is received. As yet another example, wireless device 110Amay avoid one or more subframes configured as measurement gaps. Asanother example, wireless device 110A may avoid all subframes betweenthe reception of a first trigger and the second trigger when a 2-stagegrant is used by network node 115A to allocate resources to wirelessdevice 110A.

Wireless device 110A may obtain the information related to the signaltransmission configuration in any suitable manner. As one example, incertain embodiments network node 115A may determine the informationrelated to the signal transmission configuration for autonomous ULtransmission by wireless device 110A and configure wireless device 110Ato perform autonomous UL transmission according to the determinedinformation related to the signal transmission configuration. In somecases, network node 115A may configure wireless device 110A to performautonomous UL transmission according to the determined informationrelated to the signal transmission configuration by sending thedetermined information related to the signal transmission configurationto wireless device 110A. In some cases, network node 115A may configurewireless device 110A to perform autonomous UL transmission according tothe determined information by sending, to wireless device 110A, anindication of a subframe pattern applicable to autonomous ULtransmission by wireless device 110A. The indication of the subframepattern may be in any suitable form. In certain embodiments, forexample, the indication of the subframe pattern may be a bitmap.

As another example, wireless device 110A may obtain the informationrelated to the signal transmission configuration autonomously. Forexample, the information related to the signal transmissionconfiguration may be preconfigured in wireless device 110A (for exampleat the time of manufacture). In such a scenario, upon determining thesubframes that are used, for example, for DRS, the DMTC window,measurement gaps, and/or subframes used for the first and secondtriggers of a 2-stage grant, wireless device 110A may automaticallyavoid autonomous UL transmission in one or more of those sub-frames.

In certain embodiments, to enable autonomous UL transmission, wirelessdevice 110A may be configured with SPS/IUA for certain subframes withina set of subframes or within a frame. In some cases, the configuredsubframe pattern may repeat for every new set of subframes or frame. Incertain embodiments, the configured pattern may be indicated by abitmap, for example in a bitmap received from network node 115A asdescribed above.

As noted above, autonomous UL transmission can lead to a high number ofcollisions because the UL transmissions of wireless devices 110 are notspecially coordinated at high load. In certain embodiments, the problemmay be addressed by giving wireless devices 110 (such as wirelessdevices 110A and 110B) that are configured with autonomous ULtransmissions rotating priority to start transmission in differentsubframes.

In the LTE system, certain allowed transmission starting points aredefined (e.g., once or twice per subframe). The backoff (BO) counter forthe LBT procedure may or may not be reduced continuously outside theallowed transmission period (referred to as the freeze period).Nevertheless, if the LBT procedure finishes during the freeze period,the transmission cannot start immediately, instead it is postponed untilthe next allowed transmission period.

In case of scheduled behavior, an approach may be used that reduces thebackoff counter continuously (even within the freeze period). In such ascenario, if the counter reaches 0 within an “allowed transmissionperiod,” then transmission by wireless device 110 may be commenced atthat point in time. If the counter reaches 1 within the freeze period,then transmission by a wireless device 110 is postponed to the nextallowed transmission period. In such a scenario, a wireless device 110is subject to a final CCA before transmission starts, where the FinalCCA=minimum sensing time+1 CCA slot. In certain embodiments, the minimumsensing time is 25 μs, and each CCA slot is 9 μs for LAA and MulteFireoperations in 5 GHz or 2.4 GHz bands.

For autonomous UL, the number of wireless devices 110 attempting totransmit at the same time is not controlled by a network node 115. Forinstance, if two wireless devices 110 (e.g., wireless devices 110A and110B) with different initial backoff value finish their backoff atdifferent points during the freeze period, they will both be deferreduntil the next possible allowed transmission period. Both will perform afinal CCA check. If both CCA checks succeed, they will startsimultaneous transmission and collide.

To overcome this problem and reduce the chances that different wirelessdevices 110 start their transmission at the same time, in certainembodiments a network node 115 (such as network node 115A) can spreadout the earliest possible transmission time for wireless devices 110(e.g., wireless devices 110A and 110B) with non-empty UL buffer. Thiscan be achieved by assigning different sensing durations to wirelessdevices 110A and 110B before the next possible allowed transmissionperiod (i.e., final CCA=minimum sensing time+BO slot duration*offset).By assigning different sensing durations (i.e., offset values) towireless devices 110A and 110B, this will advantageously give wirelessdevices 110A and 110B different priority to access the channel at thenext transmission period. If, for example, wireless device 110A has thesmaller offset value, if not deferred by any other ongoing interference,wireless device 110A will finish its final CCA the earliest and grab thechannel before other wireless devices 110 (such as wireless device 110B)that have higher offset values. Wireless device 110A grabs the channelby transmitting signals before the next allowed transmission boundarywhere the data transmission starts.

Wireless devices 110A and 110B may obtain their respective offset valuesin any suitable manner. In certain embodiments, the information relatedto the signal transmission configuration for autonomous UL transmissionobtained by wireless devices 110A and 110B may include an offset value.As noted above, in certain embodiments one or more of wireless devices110A and 110B may obtain the information related to the signaltransmission configuration for autonomous UL transmission, including anoffset value, autonomously. In such a scenario, one or more of wirelessdevices 110A and 110B may autonomously select an offset value (e.g.,randomly or according to one or more predefined rules).

As noted above, in certain embodiments one or more of wireless devices110A and 110B may obtain the information related to the signaltransmission configuration for autonomous UL transmission, including anoffset value, from network node 115A (for example, when network node115A determines the information related to the signal transmissionconfiguration and configures one or more of wireless devices 110A and110B to perform autonomous UL transmission according to the determinedinformation related to the signal transmission configuration). In such ascenario, network node 115A may send the determined information relatedto the signal transmission configuration, including an offset value, toone or more of wireless devices 110A and 110B.

In certain embodiments, a combination approach may be used. For example,one or more of wireless devices 110A and 110B may obtain informationrelated to the signal transmission configuration for autonomous ULtransmission from network node 115A The information related to thesignal transmission configuration obtained from network node 115A mayinclude an indication that one or more of wireless device 110A and 110Bcan use an offset value in performing autonomous UL transmission. Havingreceived an indication that an offset value can be used in performingautonomous UL transmission, one or more of wireless device 110A and 110Bmay autonomously select the offset value to be used as described above(e.g., randomly or according to one or more predefined rules). Note thatwireless devices 110A and 110B may obtain the information related to thesignal transmission configuration for autonomous UL transmission, whichmay include the offset value, in the same way or in different ways.

In certain embodiments, the priority may be statically defined. Forexample, network node 115A may use the SPS grant to set the offsets. Inthis example approach, wireless devices 110A and 110B will have fixedpriorities unless network node 115A sends a new SPS grant to update theoffset value. Network node 115A may update the offset value, forexample, using (e)PDCCH. In some cases, the priority may be dynamicallydefined. In such a scenario, access priorities among wireless devices110A and 110B are rotated. Each of wireless devices 110A and 110B obtainan offset and a rotation_periodicity. Wireless devices 110A and 110B maycalculate their respective effective offsets in subframe n as:eoffset=(offset+n)mod periodicity  (1)Wireless devices 110A and 110B then perform a final CCA of minimumsensing time+eoffset CCA slots. In some cases, the rotation_periodicitycan be set to be equal to the number of wireless devices 110 withnon-empty UL buffer. In some cases, the rotation_periodicity can be setto a number larger than the number of wireless devices 110 withnon-empty UL buffer. That is, rotation_periodicity does not need to besignaled frequently. For instance, even if the periodicity is set to 4,and the number of remaining active UL wireless devices 110 is reduced to2, the priority rotation will still work.

Wireless devices 110A and 110B may obtain the periodicity in anysuitable manner. As one example, wireless devices 110A and 110B mayobtain the periodicity autonomously. As another example, in certainembodiments network node 115A may signal the periodicity to wirelessdevices 110A and 110B via a Common Physical Downlink Control Channel(CPDCCH). As still another example, the periodicity may be configuredvia higher layer signaling (e.g., LTE RRC signaling). As anotherexample, in certain embodiments the periodicity may be fixed to acertain value. In such a scenario, the value of the periodicity may befixed to any suitable value, such as, for example, 5.

Other approaches are possible to prevent wireless devices 110 fromstarting their autonomous UL transmissions at the same time. Forexample, ensuring different wireless devices 110 start their autonomousUL transmission at different times can also be achieved if wirelessdevices 110 do not count down their random backoff counters during thefreeze period, and instead sense the channel and count their countersdown only during the periods where they are allowed to transmit. When awireless device 110 counts down to zero, it can transmit. Thisrandomizes the start times for different wireless devices 110 before thenext possible boundary where data transmission starts.

In certain embodiments, a wireless device 110 may be allowed todecrement its backoff counter for a fixed number of slots during thefreeze period, for example based on its contention window size. In sucha scenario, the wireless device 110 counts down the rest of the slotsonly during the period when it is allowed to transmit. For instance, ifwireless device 110A has a contention window size of 15, wireless device110A could be allowed to count down only 5 slots within the freezeperiod and the remaining slots must be counted down during the periodwhen it is allowed to transmit.

In some cases, it may be beneficial for a network node 115 (e.g.,network node 115A) to adapt UL access from unscheduled autonomoustransmission to schedule-based access (and vice versa), for examplebased on the load situation in a cell (e.g., cell 125A). As noted above,at high load autonomous UL transmission can lead to a high number ofcollisions and longer deferring. In such a scenario, it would bebeneficial for network node 115A to gradually adapt its behavior fromunscheduled autonomous-based UL access towards schedule-based access. Insome cases, such as in low-load situations, it may likewise bebeneficial to adapt the behavior of wireless devices 110 fromschedule-based access toward unscheduled autonomous-based UL access. Incertain embodiments, network node 115A may gradually adapt the systembehavior from unscheduled autonomous UL transmission towardschedule-based access (and vice versa) in LAA and/or standalone LTE.Employing one or more of the procedures described below mayadvantageously improve the UL performance in LAA or stand-alone LTE byavoiding collisions among wireless devices 110.

Autonomous UL is based on overbooking the same resources in frequencyand time domain for all wireless devices 110. This means wirelessdevices 110 in the same cell 125 will compete with each other to accessthe channel. This can introduce a higher collision rate due to multiplewireless devices 110 starting their transmission during the same subframe. This can be due, for example, to wireless devices 110 having thesame deferring time and/or due to wireless devices 110 not hearing eachother's transmission (e.g., due to hidden nodes).

If a network node 115 does not identify transmissions of a wirelessdevice 110 (for example due to very low Signal to Interference plusNoise Ratio (SINR)), the network node 115 cannot determine that thewireless device 110 is failing to transmit unless reported by thewireless device 110.

In certain embodiments, a network node 115 (e.g., network node 115A) cansuspend the fully autonomous UL behavior at any time for certainwireless devices 110 or for all wireless devices 110. This can beachieved in a variety of ways. Network node 115A may send, to one ormore wireless devices 110, an indication that the wireless devices 110should deactivate autonomous UL transmission. As one example, networknode 115A can send an SPS deactivation command (for example, on PDCCH)to one or more wireless devices 110. As another example, network node115A can overwrite an old SPS grant with a new SPS grant. The new SPSgrant may have a lower periodicity and/or part of the bandwidth. Thedeactivation command and/or new SPS grant may be signaled in anysuitable manner. As one example, the signaling may be done viabroadcast-type control signaling to all wireless devices 110 or a groupof wireless devices 110. As another example, the signaling may be donevia multiple dedicated control signaling to all wireless devices 110 ora subset of wireless devices 110.

Network node 115A may determine that one or more wireless devices 110should deactivate autonomous UL transmission and switch toschedule-based access based on any suitable criteria. As one example,the decision to suspend autonomous UL behavior for one or more wirelessdevices 110 may be based on one or more of: the buffer status at networknode 115A, the traffic type and the buffer build-up. For instance, ifnetwork node 115A has DL data to serve, or the DL buffer is growing,network node 115A may deactivate the autonomous UL behavior for one ormore wireless devices 110 to avoid competing with its own users toaccess the channel. Additionally, when DL traffic type has high prioritythen network node 115A can deactivate autonomous UL behavior for allwireless devices 110 to ensure fulfillment of the requirements (e.g.,data rate or delay).

As another example, the decision to suspend autonomous UL behavior forone or more wireless devices 110 may be based on the cleanliness of thechannel, which may be monitored by network node 115A. For example,network node 115A can monitor the SINR of the UL received packets andcompare it a certain threshold. The comparison may be done in anysuitable manner. In certain embodiments, the comparison can be doneconsidering the instantaneous SINR or by taking the average of N SINRsamples over a certain period of time. In some cases, the comparison canbe done at a single-wireless device level or at a cell level. As furtherexamples, the decision can be based on one or more of an unsuccessfultransmission ratio, average interference power level in the cell, andsensed energy.

As another example, the decision to suspend autonomous UL behavior forone or more wireless devices 110 may be based on a number of wirelessdevices 110 with non-empty UL buffer. As another example, the decisionto suspend autonomous UL behavior for one or more wireless devices 110may be based on a ratio of NACK to ACK for a certain one or morewireless devices 110. In some cases, different NACK to ACK ratiothresholds can be considered for scheduled and autonomous wirelessdevices 110.

As another example, the decision to suspend autonomous UL behavior forone or more wireless devices 110 may be based on the number ofcollisions on the channel where multiple wireless devices 110 attempt toaccess the channel at the same time. Network node 115A may monitorcollisions on the channel where multiple wireless devices 110 attempt toaccess the channel at the same time by detecting DMRS transmissions fromwireless devices 110. When the fraction of resources where multiple DMRStransmissions are detected exceeds a certain threshold, network node115A may suspend autonomous UL access for one or more wireless devices110 or simply reduce the number of resources available for autonomous ULaccess while shifting more wireless devices 110 to scheduled access.DMRS detection can be used in conjunction with any of the previouslylisted techniques.

It may be beneficial for network node 115A to obtain feedback from awireless device 110 about the SPS resources assigned to it. In certainembodiments, the wireless device 110 can ask network node 115 to suspendthe autonomous UL behavior by triggering a scheduling request.

For a wireless device 110 (e.g., wireless device 110A) with a non-emptyUL buffer that is using autonomous UL, network node 115A can track thetime duration since the last time it successfully received an ULtransmission from wireless device 110A. Alternatively, wireless device110A can monitor the fraction of UL resources for which collisions occuras measured by the detection of multiple DMRS patterns within asubframe. If any of the metrics above is larger than a certain threshold(i.e., wireless device 110A failed to access the channel due to highcompetition and long defer duration, or the number of collisions wasvery high), network node 115A can perform one or more of the followingoperations. As one example, network node 115A can dedicate certainresources (e.g., time and frequency) for wireless device 110A withoutoverbooking the same resources to other wireless devices 110. This mayrequire network node 115A to send a new SPS grant that overwrites theprevious SPS grant. As another example, network node 115A may considerthat as an implicit release of the SPS resources. Wireless device 110Awill be aware of the deactivation of the SPS resources as it can trackthe time since the last successful channel access.

The threshold for time between successful autonomous UL transmission canbe set in any suitable manner. As a non-limiting example, in certainembodiments the threshold for time between successful autonomous ULtransmissions can be set based on the UL traffic type or the number ofactive autonomous wireless devices 110 in the cell.

For a wireless device 110 (or group of wireless devices 110) servedusing schedule-based access in the UL, network node 115A can graduallyswitch one or more wireless devices 110 to use unscheduled access. Thedecision to switch one or more wireless devices 110 to unscheduledaccess can be made in any suitable manner and based on any suitablecriteria. As one example, the decision to switch one or more wirelessdevices 110 to unscheduled access may be made based on the buffer statusat network node 115A and the buffer build-up. If network node 115A doesnot have DL data anymore, for example, it may activate the autonomous ULbehavior to allow a wireless device 110 to access the channel during anysubframe.

As another example, the decision to switch one or more wireless devices110 to unscheduled access may be based on a number of wireless devices110 with non-empty UL buffer. If, for example, wireless device 110A isthe only remaining wireless device with non-empty buffer, network node115A may activate autonomous UL for wireless device 110A since it doesnot have any competing wireless devices in the same serving cell.

As another example, the decision to switch one or more wireless devices110 to unscheduled access may be based on a cleanliness of the channel.As noted above, network node 115A may monitor the cleanliness of thechannel. For example, network node 115A can monitor the SINR of the ULreceived packets and compare it to a certain threshold. The comparisoncan be done in any suitable manner. As a non-limiting example, thecomparison can be done considering the instantaneous SINR or by takingthe average of N SINR samples over certain period of time. Thecomparison can be done at single-wireless device level or at a celllevel. In some cases, the decision can also be based on an unsuccessfultransmission ratio, an average interference power level in the cell, orsensed energy.

As another example, the decision to switch one or more wireless devices110 to unscheduled access may be based on a NACK to ACK ratio for acertain one or more wireless devices 110. As another example, thedecision to switch one or more wireless devices 110 to unscheduledaccess may be based on the collision rate as measured by the fraction ofUL subframes where multiple DMRS signals are detected.

In certain embodiments, the decision about the SPS assigned resourcescan be based on one or more of: a cleanliness of the channel; a timeduration since the last successful channel access; the size of thecontention window of a wireless device 110; a NACK to ACK ratio; and acollision ratio based on DMRS detection.

FIG. 9 is a signal flow diagram, in accordance with certain embodiments.More particularly, FIG. 9 is a signal flow diagram illustrating anexample of avoiding specific subframes during autonomous UL transmissionby a wireless device 110. At step 904, wireless device 110 obtainsinformation related to a signal transmission configuration forautonomous UL transmission by wireless device 110. In the exampleembodiment of FIG. 9 , the information related to the signaltransmission configuration for autonomous UL transmission by wirelessdevice 110 includes information about one or more subframes that shouldbe avoided by wireless device 110 when performing autonomous ULtransmission.

As described above, wireless device 110 may obtain the informationrelated to the signal transmission configuration, including informationabout the one or more subframes that should be avoided by wirelessdevice 110 when performing autonomous UL transmission, in a variety ofways. In certain embodiments, at step 904 wireless device 110 obtainsthe information related to the signal transmission configurationautonomously. For example, the information related to the signaltransmission configuration may be preconfigured in wireless device 110(for example at the time of manufacture).

Optionally, in certain embodiments at step 902 wireless device 110 mayreceive, from network node 115, the information related to the signaltransmission configuration, including the information about the one ormore subframes that should be avoided by wireless device 110 whenperforming autonomous UL transmission. In such a scenario, wirelessdevice 110 may determine the information related to the signaltransmission configuration, including the information about the one ormore subframes that should be avoided by wireless device 110 whenperforming autonomous UL transmission, from the signal transmissionconfiguration information received from network node 115.

Wireless device 110 may be configured to avoid any suitable type ofsubframe. As one example, wireless device 110 may avoid a subframe thatnetwork node 115 (e.g., an eNB) uses to transmit the DRS. In certainembodiments, the subframe before the DRS subframe may also be avoided.As another example, wireless device 110 may avoid all subframes withinthe DMTC window, as well as the subframe before the window. As stillanother example, wireless device 110 may avoid the subframes within theDMTC window, as well as the one before the window until the DRS subframeis received. As yet another example, wireless device 110 may avoid oneor more subframes configured as measurement gaps. As another example,wireless device 110 may avoid all subframes between the reception of afirst trigger and the second trigger when a 2-stage grant is used bynetwork node 115 to allocate resources to wireless device 110. Incertain embodiments, wireless device 110 may avoid any suitablecombination of the above-described subframes.

At step 908, wireless device 110 identifies one or more subframes toavoid based on the obtained information related to the signaltransmission configuration. At step 912, wireless device 110 performsautonomous UL transmission, avoiding one or more specific subframes asindicated by the obtained information related to the signal transmissionconfiguration.

FIG. 10 is a flow diagram of a method 1000 in a wireless device, inaccordance with certain embodiments. Method 1000 begins at step 1004,where the wireless device obtains information related to a signaltransmission configuration for autonomous uplink transmission by thewireless device, the information comprising: a set of pre-allocatedresources for use by the wireless device in performing autonomous uplinktransmission on at least one secondary cell established between thewireless device and a network node; and a periodicity associated withthe set of pre-allocated resources. In certain embodiments, the at leastone secondary cell established between the wireless device and thenetwork node may be in unlicensed spectrum. In certain embodiments,obtaining information related to the signal transmission configurationfor autonomous uplink transmission by the wireless device may comprisereceiving an indication of a subframe pattern applicable to autonomousuplink transmission by the wireless device. The indication of thesubframe pattern may be a bitmap.

In certain embodiments, the information related to the signaltransmission configuration for autonomous UL transmission by thewireless device may further comprise information about one or moresubframes that should be avoided by the wireless device when performingautonomous uplink transmission. The information about one or moresubframes that should be avoided by the wireless device when performingautonomous uplink transmission may comprise one or more of an indicationof a subframe that the network node uses to transmit a discoveryreference signal and that the wireless device should avoid; and anindication of a subframe immediately preceding the subframe that thenetwork node uses to transmit the discovery reference signal and thatthe wireless device should avoid. The information about one or moresubframes that should be avoided by the wireless device when performingautonomous uplink transmission may comprise one or more of: anindication of all subframes within a discovery reference signalmeasurement timing configuration window and that the wireless deviceshould avoid; an indication of a subframe immediately preceding thediscovery reference signal measurement timing configuration window andthat the wireless device should avoid; and an indication of thesubframes within the discovery reference signal measurement timingconfiguration window and of the subframe immediately preceding thediscovery reference signal measurement timing configuration window andthat the wireless device should avoid until the wireless device receivesa discovery reference signal. The information about one or moresubframes that should be avoided by the wireless device when performingautonomous uplink transmission may comprise an indication of one or moresubframes configured as measurement gaps, and that the wireless deviceshould avoid. The information about one or more subframes that should beavoided by the wireless device when performing autonomous uplinktransmission may comprise: an indication of one or more subframesbetween reception of a first trigger and a second trigger when atwo-stage grant is used by the network node to allocate resources to thewireless device, and that the wireless device should avoid.

In certain embodiments, the information related to the signaltransmission configuration for autonomous uplink transmission by thewireless device may comprise one or more of: an offset value fordetermining a length of a sensing duration to be used by the wirelessdevice before a next allowed transmission period; and a rotationperiodicity. The method may comprise receiving at least one of theoffset value and the rotation periodicity via one or more of: a commonphysical downlink control channel; and higher layer signaling. Incertain embodiments, the offset value corresponds to a priority level ofthe wireless device for performing autonomous uplink transmissions.

In certain embodiments, the method may comprise receiving an indicationthat the wireless device should activate autonomous uplink transmission.

At step 1008, the wireless device performs autonomous uplinktransmission according to the obtained information related to the signaltransmission configuration. In certain embodiments, the method maycomprise receiving an indication that the wireless device shoulddeactivate autonomous uplink transmission. In certain embodiments, oneor more of the indication that the wireless device should deactivateautonomous uplink transmission and the indication that the wirelessdevice should activate autonomous uplink transmission may be receivedover one or more of: broadcast-type control signaling; and dedicatedcontrol signaling.

FIG. 11 is a flow diagram of a method 1100 in a network node, inaccordance with certain embodiments. The method begins at step 1104,where the network node determines information related to a signaltransmission configuration for autonomous UL transmission by a wirelessdevice, the information comprising: a set of pre-allocated resources foruse by the wireless device in performing autonomous UL transmission onat least one secondary cell established between the network node and thewireless device; and a periodicity associated with the set ofpre-allocated resources. In certain embodiments, the at least onesecondary cell established between the network node and the wirelessdevice is in unlicensed spectrum.

In certain embodiments, the information related to the signaltransmission configuration for autonomous UL transmission by thewireless device may further comprise information about one or moresubframes that should be avoided by the wireless device when performingautonomous UL transmission. The one or more subframes that should beavoided by the wireless device when performing autonomous ULtransmission may comprise one or more of: a subframe that the networknode uses to transmit a discovery reference signal; and a subframeimmediately preceding the subframe that the network node uses totransmit the discovery reference signal. The one or more subframes thatshould be avoided by the wireless device when performing autonomous ULtransmission may comprise one or more of: a subframe that the networknode uses to transmit a discovery reference signal; and a subframeimmediately preceding the subframe that the network node uses totransmit the discovery reference signal. The one or more subframes thatshould be avoided by the wireless device when performing autonomous ULtransmission may comprise one or more of: all subframes within adiscovery reference signal measurement timing configuration window; asubframe immediately preceding the discovery reference signalmeasurement timing configuration window; and the subframes within thediscovery reference signal measurement timing configuration window andthe subframe immediately preceding the discovery reference signalmeasurement timing configuration window until the wireless devicereceives a discovery reference signal. The one or more subframes thatshould be avoided by the wireless device when performing autonomous ULtransmission may comprise one or more subframes configured asmeasurement gaps. The one or more subframes that should be avoided bythe wireless device when performing autonomous UL transmission maycomprise one or more subframes between reception of a first trigger anda second trigger when a two-stage grant is used by the network node toallocate resources to the wireless device.

At step 1108, the network node configures the wireless device to performautonomous UL transmission according to the determined informationrelated to the signal transmission configuration. In certainembodiments, configuring the wireless device to perform autonomous ULtransmission according to the determined information related to thesignal transmission configuration may comprise sending the determinedinformation related to the signal transmission configuration to thewireless device.

In certain embodiments, configuring the wireless device to performautonomous UL transmission according to the determined informationrelated to the signal transmission configuration may comprise sending anindication of a subframe pattern applicable to autonomous ULtransmission by the wireless device. The indication of the subframepattern may be a bitmap.

In certain embodiments, the information related to the signaltransmission configuration for autonomous UL transmission by thewireless device may comprise one or more of an offset value fordetermining a length of a sensing duration to be used by the wirelessdevice before a next allowed transmission period; and a rotationperiodicity. The method may comprise sending at least one of the offsetvalue and the rotation periodicity to the wireless device via one ormore of a common physical downlink control channel; and higher layersignaling. In certain embodiments, the offset value corresponds to apriority level of the wireless device for performing autonomous ULtransmissions.

In certain embodiments, the method may comprise determining, based onone or more criteria, that the wireless device should deactivateautonomous UL transmission and switch to schedule-based access. The oneor more criteria may comprise one or more of: a buffer status at thenetwork node; a traffic type; a buffer build-up; a cleanliness of thechannel; a number of UEs with non-empty UL buffer; a NACK to ACK ratiofor one or more wireless devices; and a number of collisions on achannel where multiple wireless devices attempt to access the channel atthe same time. The method may comprise sending, to the wireless device,an indication that the wireless device should deactivate autonomous ULtransmission.

In certain embodiments, the method may comprise determining that thewireless device should switch from scheduled-based access to autonomousUL transmission, and sending, to the wireless device, an indication thatthe wireless device should activate autonomous UL transmission.

In certain embodiments, one or more of the indication that the wirelessdevice should deactivate autonomous UL transmission and the indicationthat the wireless device should activate autonomous UL transmission maybe sent using one or more of: broadcast-type control signaling; anddedicated control signaling.

FIG. 12 is a block schematic of an exemplary wireless device, inaccordance with certain embodiments. Wireless device 110 may refer toany type of wireless device communicating with a node and/or withanother wireless device in a cellular or mobile communication system.Examples of wireless device 110 include a mobile phone, a smart phone, aPDA (Personal Digital Assistant), a portable computer (e.g., laptop,tablet), a sensor, a modem, a machine-type-communication (MTC)device/machine-to-machine (M2M) device, laptop embedded equipment (LEE),laptop mounted equipment (LME), USB dongles, a D2D capable device, oranother device that can provide wireless communication. A wirelessdevice 110 may also be referred to as UE, a station (STA), a device, ora terminal in some embodiments. Wireless device 110 includes transceiver1210, processor 1220, and memory 1230. In some embodiments, transceiver1210 facilitates transmitting wireless signals to and receiving wirelesssignals from network node 115 (e.g., via antenna 1240), processor 1220executes instructions to provide some or all of the functionalitydescribed above as being provided by wireless device 110, and memory1230 stores the instructions executed by processor 1220.

Processor 1220 may include any suitable combination of hardware andsoftware implemented in one or more modules to execute instructions andmanipulate data to perform some or all of the described functions ofwireless device 110, such as the functions of wireless device 110described above in relation to FIGS. 1-11 . In some embodiments,processor 1220 may include, for example, one or more computers, one ormore central processing units (CPUs), one or more microprocessors, oneor more applications, one or more application specific integratedcircuits (ASICs), one or more field programmable gate arrays (FPGAs)and/or other logic.

Memory 1230 is generally operable to store instructions, such as acomputer program, software, an application including one or more oflogic, rules, algorithms, code, tables, etc. and/or other instructionscapable of being executed by a processor. Examples of memory 1230include computer memory (for example, Random Access Memory (RAM) or ReadOnly Memory (ROM)), mass storage media (for example, a hard disk),removable storage media (for example, a Compact Disk (CD) or a DigitalVideo Disk (DVD)), and/or or any other volatile or non-volatile,non-transitory computer-readable and/or computer-executable memorydevices that store information, data, and/or instructions that may beused by processor 1020.

Other embodiments of wireless device 110 may include additionalcomponents beyond those shown in FIG. 12 that may be responsible forproviding certain aspects of the wireless device's functionality,including any of the functionality described above and/or any additionalfunctionality (including any functionality necessary to support thesolution described above). As just one example, wireless device 110 mayinclude input devices and circuits, output devices, and one or moresynchronization units or circuits, which may be part of the processor1220. Input devices include mechanisms for entry of data into wirelessdevice 110. For example, input devices may include input mechanisms,such as a microphone, input elements, a display, etc. Output devices mayinclude mechanisms for outputting data in audio, video and/or hard copyformat. For example, output devices may include a speaker, a display,etc.

FIG. 13 is a block schematic of an exemplary network node, in accordancewith certain embodiments. Network node 115 may be any type of radionetwork node or any network node that communicates with a UE and/or withanother network node. Examples of network node 115 include an eNodeB, anode B, a base station, a wireless access point (e.g., a Wi-Fi accesspoint), a low power node, a base transceiver station (BTS), relay, donornode controlling relay, transmission points, transmission nodes, remoteRF unit (RRU), remote radio head (RRH), multi-standard radio (MSR) radionode such as MSR BS, nodes in distributed antenna system (DAS), O&M,OSS, SON, positioning node (e.g., E-SMLC), MDT, or any other suitablenetwork node. Network nodes 115 may be deployed throughout network 100as a homogenous deployment, heterogeneous deployment, or mixeddeployment. A homogeneous deployment may generally describe a deploymentmade up of the same (or similar) type of network nodes 115 and/orsimilar coverage and cell sizes and inter-site distances. Aheterogeneous deployment may generally describe deployments using avariety of types of network nodes 115 having different cell sizes,transmit powers, capacities, and inter-site distances. For example, aheterogeneous deployment may include a plurality of low-power nodesplaced throughout a macro-cell layout. Mixed deployments may include amix of homogenous portions and heterogeneous portions.

Network node 115 may include one or more of transceiver 1310, processor1320, memory 1330, and network interface 1340. In some embodiments,transceiver 1310 facilitates transmitting wireless signals to andreceiving wireless signals from wireless device 110 (e.g., via antenna1350), processor 1320 executes instructions to provide some or all ofthe functionality described above as being provided by a network node115, memory 1330 stores the instructions executed by processor 1320, andnetwork interface 1340 communicates signals to backend networkcomponents, such as a gateway, switch, router, Internet, Public SwitchedTelephone Network (PSTN), core network nodes or radio networkcontrollers 130, etc.

Processor 1320 may include any suitable combination of hardware andsoftware implemented in one or more modules to execute instructions andmanipulate data to perform some or all of the described functions ofnetwork node 115, such as those described above in relation to FIGS.1-11 above. In some embodiments, processor 1320 may include, forexample, one or more computers, one or more CPUs, one or moremicroprocessors, one or more applications, one or more ASICs, one ormore FPGAs and/or other logic.

Memory 1330 is generally operable to store instructions, such as acomputer program, software, an application including one or more oflogic, rules, algorithms, code, tables, etc. and/or other instructionscapable of being executed by a processor. Examples of memory 1330include computer memory (for example, RAM or ROM), mass storage media(for example, a hard disk), removable storage media (for example, a CDor a DVD), and/or or any other volatile or non-volatile, non-transitorycomputer-readable and/or computer-executable memory devices that storeinformation.

In some embodiments, network interface 1340 is communicatively coupledto processor 1320 and may refer to any suitable device operable toreceive input for network node 115, send output from network node 115,perform suitable processing of the input or output or both, communicateto other devices, or any combination of the preceding. Network interface1340 may include appropriate hardware (e.g., port, modem, networkinterface card, etc.) and software, including protocol conversion anddata processing capabilities, to communicate through a network.

Other embodiments of network node 115 may include additional componentsbeyond those shown in FIG. 13 that may be responsible for providingcertain aspects of the radio network node's functionality, including anyof the functionality described above and/or any additional functionality(including any functionality necessary to support the solutionsdescribed above). The various different types of network nodes mayinclude components having the same physical hardware but configured(e.g., via programming) to support different radio access technologies,or may represent partly or entirely different physical components.

FIG. 14 is a block schematic of an exemplary radio network controller orcore network node 130, in accordance with certain embodiments. Examplesof network nodes can include a mobile switching center (MSC), a servingGPRS support node (SGSN), a mobility management entity (MME), a radionetwork controller (RNC), a base station controller (BSC), and so on.The radio network controller or core network node 130 includes processor1420, memory 1430, and network interface 1440. In some embodiments,processor 1420 executes instructions to provide some or all of thefunctionality described above as being provided by the network node,memory 1430 stores the instructions executed by processor 1420, andnetwork interface 1440 communicates signals to any suitable node, suchas a gateway, switch, router, Internet, Public Switched TelephoneNetwork (PSTN), network nodes 115, radio network controllers or corenetwork nodes 130, etc.

Processor 1420 may include any suitable combination of hardware andsoftware implemented in one or more modules to execute instructions andmanipulate data to perform some or all of the described functions of theradio network controller or core network node 130. In some embodiments,processor 1420 may include, for example, one or more computers, one ormore CPUs, one or more microprocessors, one or more applications, one ormore ASICs, one or more FPGAs and/or other logic.

Memory 1430 is generally operable to store instructions, such as acomputer program, software, an application including one or more oflogic, rules, algorithms, code, tables, etc. and/or other instructionscapable of being executed by a processor. Examples of memory 1430include computer memory (for example, RAM or ROM), mass storage media(for example, a hard disk), removable storage media (for example, a CDor a DVD), and/or or any other volatile or non-volatile, non-transitorycomputer-readable and/or computer-executable memory devices that storeinformation.

In some embodiments, network interface 1440 is communicatively coupledto processor 1420 and may refer to any suitable device operable toreceive input for the network node, send output from the network node,perform suitable processing of the input or output or both, communicateto other devices, or any combination of the preceding. Network interface1440 may include appropriate hardware (e.g., port, modem, networkinterface card, etc.) and software, including protocol conversion anddata processing capabilities, to communicate through a network.

Other embodiments of the network node may include additional componentsbeyond those shown in FIG. 14 that may be responsible for providingcertain aspects of the network node's functionality, including any ofthe functionality described above and/or any additional functionality(including any functionality necessary to support the solution describedabove).

FIG. 15 is a block schematic of an exemplary wireless device, inaccordance with certain embodiments. Wireless device 110 may include oneor more modules. For example, wireless device 110 may include adetermining module 1510, a communication module 1520, a receiving module1530, an input module 1540, a display module 1550, and any othersuitable modules. In some embodiments, one or more of determining module1510, communication module 1520, receiving module 1530, input module1540, display module 1550 or any other suitable module may beimplemented using one or more processors, such as processor 1220described above in relation to FIG. 12 . Wireless device 110 may performthe methods for collision avoidance adaptation for autonomoustransmission systems described above with respect to FIGS. 1-11 .

Determining module 1510 may perform the processing functions of wirelessdevice 110. For example, determining module 1510 may obtain informationrelated to a signal transmission configuration for autonomous ULtransmission by the wireless device. In certain embodiments, determiningmodule 1510 may obtain information related to the signal transmissionconfiguration for autonomous UL transmission by wireless device 110 byautonomously determining the information related to the signaltransmission configuration. Determining module 1510 may include or beincluded in one or more processors, such as processor 1220 describedabove in relation to FIG. 12 . Determining module 1510 may includeanalog and/or digital circuitry configured to perform any of thefunctions of determining module 1510 and/or processor 1220 describedabove. The functions of determining module 1510 described above may, incertain embodiments, be performed in one or more distinct modules.

Communication module 1520 may perform the transmission functions ofwireless device 110. For example, communication module 1520 may performautonomous UL transmission according to the obtained information relatedto the signal transmission configuration. In certain embodiments,communication module 1520 may perform autonomous UL transmission whileavoiding one or more specific subframes. Communication module 1520 maytransmit messages to one or more of network nodes 115 of network 100.Communication module 1520 may include a transmitter and/or atransceiver, such as transceiver 1210 described above in relation toFIG. 12 . Communication module 1520 may include circuitry configured towirelessly transmit messages and/or signals. In particular embodiments,communication module 1520 may receive messages and/or signals fortransmission from determining module 1510. In certain embodiments, thefunctions of communication module 1520 described above may be performedin one or more distinct modules.

Receiving module 1530 may perform the receiving functions of wirelessdevice 110. As one example, receiving module 1530 may obtain informationrelated to a signal transmission configuration for autonomous ULtransmission by wireless device 110. In some cases, receiving module1530 may obtain information related to the signal transmissionconfiguration for autonomous UL transmission by receiving theinformation related to the signal transmission configuration from anetwork node. As another example, receiving module 1530 may receive anindication of a subframe pattern applicable to autonomous uplinktransmission by wireless device 110. As still another example, receivingmodule 1530 may receive at least one of an offset value and a rotationperiodicity via one or more of: a common physical downlink controlchannel; and higher layer signaling. As another example, receivingmodule 1530 may receive an indication that wireless device 110 shoulddeactivate autonomous UL transmission. As another example, receivingmodule 1530 may receive one of a semi-persistent schedule deactivationcommand and a new semi-persistent scheduling grant. As another example,receiving module 1530 may receive an indication that wireless device 110should activate autonomous UL activity.

Receiving module 1530 may include a receiver and/or a transceiver, suchas transceiver 1210 described above in relation to FIG. 12 . Receivingmodule 1530 may include circuitry configured to wirelessly receivemessages and/or signals. In particular embodiments, receiving module1530 may communicate received messages and/or signals to determiningmodule 1510. The functions of receiving module 1530 described above may,in certain embodiments, be performed in one or more distinct modules.

Input module 1540 may receive user input intended for wireless device110. For example, the input module may receive key presses, buttonpresses, touches, swipes, audio signals, video signals, and/or any otherappropriate signals. The input module may include one or more keys,buttons, levers, switches, touchscreens, microphones, and/or cameras.The input module may communicate received signals to determining module1510.

Display module 1550 may present signals on a display of wireless device110. Display module 1550 may include the display and/or any appropriatecircuitry and hardware configured to present signals on the display.Display module 1550 may receive signals to present on the display fromdetermining module 1510.

Determining module 1510, communication module 1520, receiving module1530, input module 1540, and display module 1550 may include anysuitable configuration of hardware and/or software. Wireless device 110may include additional modules beyond those shown in FIG. 15 that may beresponsible for providing any suitable functionality, including any ofthe functionality described above and/or any additional functionality(including any functionality necessary to support the various solutionsdescribed herein).

FIG. 16 is a block schematic of an exemplary network node 115, inaccordance with certain embodiments. Network node 115 may include one ormore modules. For example, network node 115 may include determiningmodule 1610, communication module 1620, receiving module 1630, and anyother suitable modules. In some embodiments, one or more of determiningmodule 1610, communication module 1620, receiving module 1630, or anyother suitable module may be implemented using one or more processors,such as processor 1320 described above in relation to FIG. 13 . Incertain embodiments, the functions of two or more of the various modulesmay be combined into a single module. Network node 115 may perform themethods for collision avoidance adaptation for autonomous transmissionsystems described above with respect to FIGS. 1-11 .

Determining module 1610 may perform the processing functions of networknode 115. For example, determining module 1610 may determine informationrelated to a signal transmission configuration for autonomous ULtransmission by a wireless device. As another example, determiningmodule 1610 may configure the wireless device to perform autonomous ULtransmission according to the determined information related to thesignal transmission configuration. As another example, determiningmodule 1610 may determine, based on one or more criteria, that thewireless device should deactivate autonomous UL transmission and switchto schedule-based access. As still another example, determining module1610 may determine that the wireless device should switch fromscheduled-based access to autonomous UL transmission.

As another example, determining module 1610 may determine a networkload. As yet another example, determining module 1610 may determinewhether a wireless device has data in an UL buffer. As still anotherexample, determining module 1610 may determine whether to suspendautonomous UL transmission for a particular one of the one or morewireless devices. As another example, determining module 1610 maymonitor collisions on a channel where one or more wireless devicesattempt to access the channel at the same time by detecting DMRStransmissions from the one or more wireless devices, determining whethera fraction of resources where multiple DMRS transmissions are detectedexceeds a threshold, and performing one or more of: suspendingautonomous UL transmission for one or more wireless devices; reducing anumber of resources available for autonomous UL transmission; andshifting some of the one or more wireless devices to scheduled ULaccess. As yet another example, determining module 1610 may determinewhether a time duration since the network node last received an ULtransmission from a particular wireless device exceeds a threshold. Upondetermining that the time duration exceeds the threshold, determiningmodule 1610 may perform one or more of: dedicate one or more resourcesto the particular wireless device without overbooking the same resourcesto other wireless devices; and release SPS resources for the particularwireless device. As another example, determining module 1610 may monitora fraction of UL resources for which collisions occur. As still anotherexample, determining module 1610 may determine that one or more wirelessdevices configured to use schedule-based access in the UL should beswitched to unscheduled access.

Determining module 1610 may include or be included in one or moreprocessors, such as processor 1320 described above in relation to FIG.13 . Determining module 1610 may include analog and/or digital circuitryconfigured to perform any of the functions of determining module 1610and/or processor 1320 described above. The functions of determiningmodule 1610 may, in certain embodiments, be performed in one or moredistinct modules.

Communication module 1620 may perform the transmission functions ofnetwork node 115. As one example, communication module 1620 may send thedetermined information related to the signal transmission configurationto the wireless device. As another example, communication module 1620may send an indication of a subframe pattern applicable to autonomous ULtransmission by the wireless device. As still another example,communication module 1620 may send at least one of an offset value and arotation periodicity to the wireless device via one or more of: a commonphysical downlink control channel; and higher layer signaling. Asanother example, communication module 1620 may send, to the wirelessdevice, an indication that the wireless device should deactivateautonomous UL transmission. As another example, communication module1620 may send, to the wireless device, an indication that the wirelessdevice should activate autonomous UL transmission. As another example,communication module 1620 may send, to the one or more UEs, anindication that the one or more wireless devices should suspendautonomous UL transmission. As still another example, communicationmodule 1620 may send one of a semi-persistent scheduling deactivationcommand and a new semi-persistent scheduling grant.

Communication module 1620 may transmit messages to one or more ofwireless devices 110. Communication module 1620 may include atransmitter and/or a transceiver, such as transceiver 1310 describedabove in relation to FIG. 13 . Communication module 1620 may includecircuitry configured to wirelessly transmit messages and/or signals. Inparticular embodiments, communication module 1620 may receive messagesand/or signals for transmission from determining module 1610 or anyother module. The functions of communication module 1620 may, in certainembodiments, be performed in one or more distinct modules.

Receiving module 1630 may perform the receiving functions of networknode 115. For example, receiving module 1630 may receive feedback fromone or more wireless devices about semi-persistent scheduling resourcesassigned to the one or more wireless devices. As another example,receiving module 1630 may receive a request from a particular one of theone or more wireless devices requesting that the network node suspendautonomous UL transmission. Receiving module 1630 may receive anysuitable information from a wireless device. Receiving module 1630 mayinclude a receiver and/or a transceiver, such as transceiver 1310described above in relation to FIG. 13 . Receiving module 1630 mayinclude circuitry configured to wirelessly receive messages and/orsignals. In particular embodiments, receiving module 1630 maycommunicate received messages and/or signals to determining module 1610or any other suitable module. The functions of receiving module 1630may, in certain embodiments, be performed in one or more distinctmodules.

Determining module 1610, communication module 1620, and receiving module1630 may include any suitable configuration of hardware and/or software.Network node 115 may include additional modules beyond those shown inFIG. 16 that may be responsible for providing any suitablefunctionality, including any of the functionality described above and/orany additional functionality (including any functionality necessary tosupport the various solutions described herein).

Modifications, additions, or omissions may be made to the systems andapparatuses described herein without departing from the scope of thedisclosure. The components of the systems and apparatuses may beintegrated or separated. Moreover, the operations of the systems andapparatuses may be performed by more, fewer, or other components.Additionally, operations of the systems and apparatuses may be performedusing any suitable logic comprising software, hardware, and/or otherlogic. As used in this document, “each” refers to each member of a setor each member of a subset of a set.

Modifications, additions, or omissions may be made to the methodsdescribed herein without departing from the scope of the disclosure. Themethods may include more, fewer, or other steps. Additionally, steps maybe performed in any suitable order.

Although this disclosure has been described in terms of certainembodiments, alterations and permutations of the embodiments will beapparent to those skilled in the art. Accordingly, the above descriptionof the embodiments does not constrain this disclosure. Other changes,substitutions, and alterations are possible without departing from thespirit and scope of this disclosure, as defined by the following claims.

Abbreviations used in the preceding description include:

-   -   3GPP 3^(rd) Generation Partnership Project    -   ACK Acknowledgement    -   AP Access Point    -   ASIC Application Specific Integrated Circuit    -   BO Backoff    -   BS Base Station    -   BSC Base Station Controller    -   BSR Buffer Status Report    -   BTS Base Transceiver Station    -   CA Carrier Aggregation    -   CCA Clear Channel Assessment    -   CD Compact Disk    -   CE Control Element    -   CFI Control Format Indicator    -   CPDCCH Common Physical Downlink Control Channel    -   CPE Customer Premises Equipment    -   CPU Central Processing Unit    -   CRC Cyclic Redundancy Check    -   C-RNTI Cell Radio Network Temporary Identifier    -   CRS Cell-Specific Reference Symbols    -   CSI-RS Channel State Information Reference Signal    -   CSMA/CA Carrier Sense Multiple Access with Collision Avoidance    -   D2D Device-to-device    -   DAS Distributed Antenna System    -   DCI Downlink Control Information    -   DIES Distributed Inter-Frame Space    -   DL Downlink    -   DMRS Demodulation Reference Signals    -   DMTC DRS Measurement Time Configuration    -   DRS Discovery Reference Signal    -   DVD Digital Video Disk    -   eNB evolved Node B    -   EPDCCH Enhanced Physical Downlink Control Channel    -   E-SMLC Evolved Serving Mobile Location Center    -   ETSI European Telecommunications Standards Institute    -   E-UTRAN Evolved Universal Terrestrial Radio Access Network    -   FPGA Field Programmable Gate Array    -   IoT Internet of Things    -   IP Internet Protocol    -   IUA Instant Uplink Access    -   LAA Licensed-Assisted Access    -   LAN Local Area Network    -   LBT Listen-Before-Talk    -   LEE Laptop Embedded Equipment    -   LME Laptop Mounted Equipment    -   LTE Long Term Evolution    -   M2M Machine-to-Machine    -   MAC Medium Access Control    -   MAN Metropolitan Area Network    -   MCE Multi-cell/multicast Coordination Entity    -   MCS Modulation level and coding scheme    -   MDT Minimization of Drive Test    -   MME Mobility Management Entity    -   MSC Mobile Switching Center    -   MSR Multi-standard Radio    -   MTC Machine-Type Communication    -   NACK Negative Acknowledgement    -   NAS Non-Access Stratum    -   NB-IoT Narrow band Internet of Things    -   NR New Radio    -   O&M Operations and Management    -   OFDM Orthogonal Frequency Division Multiplexing    -   OSS Operations Support System    -   PCell Primary Cell    -   PDCCH Physical Downlink Control Channel    -   PSS Primary Synchronization Signal    -   PSTN Public Switched Telephone Network    -   PUCCH Physical Uplink Control Channel    -   PUSCH Physical Uplink Shared Channel    -   RA Random Access    -   RAM Random Access Memory    -   RAN Radio Access Network    -   RAT Radio Access Technology    -   RNC Radio Network Controller    -   ROM Read-Only Memory    -   RRC Radio Resource Control    -   RRH Remote Radio Head    -   RRM Radio Resource Management    -   RRU Remote Radio Unit    -   SCell Secondary Cell    -   SC-FDMA Single-Carrier Frequency Division Multiple Access    -   SIB Session Information Block    -   SINR Signal to Interference plus Noise Ratio    -   SON Self-Organizing Network    -   SPS Semi-Persistent Scheduling    -   SR Scheduling Request    -   SRS Sounding Reference Signal    -   SSS Secondary Synchronization Signal    -   TDMA Time Division Multiple Access    -   TR Technical Report    -   TS Technical Specification    -   TTI Transmission Time Interval    -   UE User Equipment    -   UL Uplink    -   UP User Plane    -   WAN Wide Area Network    -   WLAN Wireless Local Area Network

The invention claimed is:
 1. A method in a wireless device, comprising:obtaining information related to a signal transmission configuration forautonomous uplink transmission by the wireless device, the informationcomprising: a set of pre-allocated resources for use by the wirelessdevice in performing autonomous uplink transmission on a cellestablished between the wireless device and a network node and operatingin unlicensed spectrum, wherein the set of pre-allocated resources havea periodicity; and performing autonomous uplink transmission accordingto the obtained information related to the signal transmissionconfiguration.
 2. The method of claim 1, wherein obtaining informationrelated to the signal transmission configuration for autonomous uplinktransmission by the wireless device comprises: receiving an indicationof a subframe pattern applicable to autonomous uplink transmission bythe wireless device.
 3. The method of claim 1, wherein the indication ofthe subframe pattern is a bitmap.
 4. The method of claim 1, wherein theinformation related to the signal transmission configuration forautonomous uplink transmission by the wireless device comprises one ormore of: an offset value for determining a length of a sensing durationto be used by the wireless device before a next allowed transmissionperiod; and a rotation periodicity.
 5. The method of claim 1, comprisingreceiving at least one of the offset value and the rotation periodicityvia one or more of: a common physical downlink control channel; andhigher layer signaling.
 6. The method of claim 1, wherein the offsetvalue corresponds to a priority level of the wireless device forperforming autonomous uplink transmissions.
 7. The method of claim 1,comprising: receiving an indication that the wireless device shoulddeactivate autonomous uplink transmission, wherein the indication thatthe wireless device should deactivate autonomous uplink transmission isreceived over one or more of: broadcast-type control signaling; anddedicated control signaling.
 8. The method of claim 1, furthercomprising: switching from an autonomous uplink transmission mode to anetwork-node controlled scheduling mode.
 9. The method of claim 8,wherein the switching is performed dynamically based on load.
 10. Amethod in a network node, comprising: determining information related toa signal transmission configuration for autonomous uplink transmissionby a wireless device, the information comprising: a set of pre-allocatedresources for use by the wireless device in performing autonomous uplinktransmission on a cell established between the network node and thewireless device and operating in unlicensed spectrum, wherein the set ofpre-allocated resources have a periodicity; and configuring the wirelessdevice to perform autonomous uplink transmission according to thedetermined information related to the signal transmission configuration.11. The method of claim 10, wherein configuring the wireless device toperform autonomous uplink transmission according to the determinedinformation related to the signal transmission configuration comprises:sending an indication of a subframe pattern applicable to autonomousuplink transmission by the wireless device wherein the indication of thesubframe pattern is a bitmap.
 12. The method of claim 10, wherein theinformation related to the signal transmission configuration forautonomous uplink transmission by the wireless device comprises one ormore of: an offset value for determining a length of a sensing durationto be used by the wireless device before a next allowed transmissionperiod; and a rotation periodicity.
 13. The method of claim 10,comprising sending at least one of the offset value and the rotationperiodicity to the wireless device via one or more of: a common physicaldownlink control channel; and higher layer signaling.
 14. The method ofclaim 10, wherein the offset value corresponds to a priority level ofthe wireless device for performing autonomous uplink transmissions. 15.The method of claim 10, comprising: determining, based on one or morecriteria, that the wireless device should deactivate autonomous uplinktransmission and switch to schedule-based access, wherein the one ormore criteria comprise one or more of: a buffer status at the networknode; a traffic type; a buffer build-up; a cleanliness of the channel; anumber of UEs with non-empty UL buffer; a NACK to ACK ratio for one ormore wireless devices; and a number of collisions on a channel wheremultiple wireless devices attempt to access the channel at the sametime; and sending, to the wireless device, an indication that thewireless device should deactivate autonomous uplink transmission. 16.The method of claim 10, wherein the indication that the wireless deviceshould deactivate autonomous uplink transmission is sent using one ormore of: broadcast-type control signaling; and dedicated controlsignaling.
 17. The method of claim 10, further comprising: configuringthe wireless device to switch from an autonomous uplink transmissionmode to a network-node controlled scheduling mode.
 18. The method ofclaim 17, wherein the switching is performed dynamically based on load.19. A wireless device, comprising: processing circuitry, the processingcircuitry configured to: obtain information related to a signaltransmission configuration for autonomous uplink transmission by thewireless device, the information comprising: a set of pre-allocatedresources for use by the wireless device in performing autonomous uplinktransmission on a cell established between the wireless device and anetwork node and operating in unlicensed spectrum, wherein the set ofpre-allocated resources have a periodicity; and perform autonomousuplink transmission according to the obtained information related to thesignal transmission configuration.
 20. A network node, comprising:processing circuitry, the processing circuitry configured to: determineinformation related to a signal transmission configuration forautonomous uplink transmission by a wireless device, the informationcomprising: a set of pre-allocated resources for use by the wirelessdevice in performing autonomous uplink transmission on a cellestablished between the network node and the wireless device andoperating in unlicensed spectrum, wherein the set of pre-allocatedresources have a periodicity; and configure the wireless device toperform autonomous uplink transmission according to the determinedinformation related to the signal transmission configuration.